A chemically amplified radiation-sensitive composition generates an acid when exposed to deep ultraviolet rays such as a KrF excimer laser and an ArF excimer laser, and produces a solubility rate difference between an exposed area and a non-exposed area in a developing solution by a chemical reaction catalyzed by the acid, thereby forming a resist pattern on a substrate.
For example, when a KrF excimer laser (wavelength: 248 nm) is used as a light source, it is possible to form an excellent pattern with high sensitivity and high resolution by using a chemically amplified radiation-sensitive composition containing a polymer having a polyhydroxystyrene (hereinafter referred to from time to time as “PHS”) skeleton having a small absorbance of a light with a wavelength of 248 nm as a main component.
On the other hand, in order to form a more minute pattern, an ArF excimer laser (wavelength: 193 nm) is used as a light source having a shorter wavelength. A compound having an aromatic group such as PHS cannot be suitably used when an ArF excimer laser is used as a light source due to possession of a large absorbance at a wavelength of 193 nm which is the wavelength of an ArF excimer laser. Therefore, a radiation-sensitive composition containing a polymer having an alicyclic hydrocarbon skeleton which does not have a large absorbance at a wavelength of 193 nm has been used in a lithographic process using an ArF excimer laser.
Such a composition has been found to exhibit outstanding improvement in resolution performance as a resist if the polymer having an alicyclic hydrocarbon skeleton includes a repeating unit having a lactone skeleton.
For example, Patent Documents 1 and 2 describe a radiation-sensitive composition having a repeating unit with a mevalolactone skeleton or a γ-butyrolactone skeleton, and Patent Documents 3 to 13 describe a radiation-sensitive composition having a repeating unit with an alicyclic lactone skeleton.    Patent Document 1: Japanese Patent Application Publication (KOKAI) No. 9-73173    Patent Document 2: U.S. Pat. No. 6,388,101    Patent Document 3: Japanese Patent Application Publication (KOKAI) No. 2000-159758    Patent Document 4: Japanese Patent Application Publication (KOKAI) No. 2001-109154    Patent Document 5: Japanese Patent Application Publication (KOKAI) No. 2004-101642    Patent Document 6: Japanese Patent Application Publication (KOKAI) No. 2003-113174    Patent Document 7: Japanese Patent Application Publication (KOKAI) No. 2003-147023    Patent Document 8: Japanese Patent Application Publication (KOKAI) No. 2002-308866    Patent Document 9: Japanese Patent Application Publication (KOKAI) No. 2002-371114    Patent Document 10: Japanese Patent Application Publication (KOKAI) No. 2003-64134    Patent Document 11: Japanese Patent Application Publication (KOKAI) No. 2003-270787    Patent Document 12: Japanese Patent Application Publication (KOKAI) No. 2000-26446    Patent Document 13: Japanese Patent Application Publication (KOKAI) No. 2000-122294